Unconventional superconducting phase in NbSe<sub>2</sub>-based misfit layered superconductor

ORAL

Abstract

Two-dimensional (2D) superconductor is a good playground for investigating quantum transport. Recently, bulk 2D superconductors, where superconducting layers are well separated by non-superconducting block layers, has been intensively studied [1,2]. Among them, misfit layered compound, which consist of alternately stacked layers with incompatible unit cells [3], is a unique material, offering a new opportunity for exploring low dimensional superconductivity.

In this work, we report transport properties of misfit layered superconductor composed of NbSe2. In this material, trilayer NbSe2 layers are separated by PbSe block layers. Firstly, we found that the superconducting transition temperature is close to the exfoliated trilayer NbSe2. Secondly, we observed an anomaly in temperature dependence of in-plane upper critical field, which suggests the unconventional superconductivity in low-temperature and high-magnetic-field region. Since this anomaly is absent in bulk and exfoliated trilayer NbSe2 [4,5], we assume that PbSe block layers play crucial role in the emergence of unconventional superconducting phase in the present system.

[1] A. Devarakonda et al., Science 370, 231 (2020).

[2] P. Samuely et al., PRB 104, 224507 (2021).

[3] N. Ng and T. M. McQueen, APL Mater. 10, 100901 (2022).

[4] X. Xi et al., Nat. Phys. 12, 139 (2016).

[5] E. Sohn et al., Nat. Commun. 17, 504 (2018).

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Presenters

  • Yuki Itahashi

    • Univ of Tokyo
    • Department of Applied Physics, The University of Tokyo; RIKEN

Authors

  • Yuki Itahashi

    • Univ of Tokyo
    • Department of Applied Physics, The University of Tokyo; RIKEN

  • Yamato Nohara

    • Department of Applied Physics, The University of Tokyo

  • Michiya Chazono

    • Department of Physics, Graduate School of Science, Kyoto University, Kyoto 606-8502, Japan

  • Hideki Matsuoka

    • The University of Tokyo
    • RIKEN CEMS

  • Koichiro Arioka

    • Research Institute for Interdisciplinary Science, Okayama University, Okayama 700-8530, Japan

  • Tetsuya Nomoto

    • The Institute for Solid State Physics, The University of Tokyo,

  • Yoshimitsu Kohama

    • The Institute for Solid State Physics, The University of Tokyo
    • University of Tokyo
    • ISSP
    • Institute for Solid State Physics, University of Tokyo

  • Youichi Yanase

    • Kyoto Univ

  • Yoshihiro Iwasa

    • Univ of Tokyo
    • The University of Tokyo
    • The University of Tokyo, RIKEN CEMS
    • Univ of Tokyo, RIKEN

  • Kaya Kobayashi

    • Okayama Univ